1. Field of the Invention
The present invention relates to an injector nozzle and a manufacturing method of the same.
2. Description of Related Art
An injector nozzle is a device for injecting pressurized fluid through a small hole or aperture. For example, an injector nozzle is used for a fuel injector. In such the application, the fuel injector has an orifice as the small hole, and injects fuel into an intake air passage or a combustion chamber. The orifice defines a flow rate and is a principal part for metering an amount of injected fuel. Therefore, it is important to process the orifice precisely.
JP-A-9-209876 discloses a fuel injector and a manufacturing method of the same. In this document, pressurized liquid containing abrasive particles is forcedly run through a hole in order to form a chamfered shoulder on an inlet of the hole. During the processing, a flow rate of the liquid is measured and monitored in order to stop the processing when the measured flow rate reaches to a predetermined value. As a result, it is possible to form a precision hole.
However, in certain applications, the pressurized liquid with abrasive particles may damage a member having the orifice or aperture. For example, in case of a thin plate having an orifice, the thin plate may be deformed by the pressurized liquid.
In another aspect, if a burr remains when flowing the liquid with abrasive particles, the burr may affect the flow and may form uneven flow of the liquid. As a result, the orifice may be trimmed in an undesirable shape.